#!/bin/python3

import sys
numbers = "0123456789"
lower_case = "abcdefghijklmnopqrstuvwxyz"
upper_case = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
spl_chars = "!@#$%^&*()-+"
def minimumNumber(n, password):
    # Return the minimum number of characters to make the password strong
    nf=0
    lc=0
    uc=0
    sc=0
    cntr=0
    for x in password:
        if x in numbers:
            nf=1
        elif x in lower_case:
            lc=1
        elif x in upper_case:
            uc=1
        elif x in spl_chars:
            sc=1
    if(nf==0):
        cntr+=1
    if(lc==0):
        cntr+=1
    if(uc==0):
        cntr+=1
    if(sc==0):
        cntr+=1
    if(len(password)>6):
        return cntr
    else:
        if(len(password)+cntr<6):
            return (6-len(password))
        else:
            return cntr

if __name__ == "__main__":
    n = int(input().strip())
    password = input().strip()
    answer = minimumNumber(n, password)
    print(answer)